Interrupter attachment for disconnect switch



Feb. 25, 1958 P. M. HASLAM 2,824,935

INTERRUPTER ATTACHMENT FOR DISCONNECT SWITCH Filed Jan. 24, 1955 4 Sheets-Sheet l INVENTORI P140 M. H/osm M Feb. 25, 1958 P. M. HASLAM INTERRUPTER ATTACHMENT FOR DISCONNECT SWITCH Filed Jan. 24, 1955 4 Sheets-Sheet 2 INVEN TOR Wik Feb. 25, 1958 P. M. HASLAM 2,324,935

INTERRUPTER ATTACHMENT FOR DISCONNECT SWITCH Filed Jan. 24, 1955 4 Sheets-Sheet 4 IH QW I N w mm UnitedStates Patent INTERRUPTER ATTACHMENT FOR DISCONNECT SWITCH Paul M. Haslam, Greensburg, Pa., assignor to I-T-E Circuit Breaker Company, Philadelphia, Pa., a corporation of Pennsylvania Application January 24, 1955, Serial No. 483,737 Claims. (Cl. 200-146) My invention relates to an interrupter attachment for adisconnect switch and more particularly is directed to a novel attachment wherein the cooperating contacts of the interrupter attachment are moved in straight-line motion with snapaction from the engaged to disengaged position, and vice versa, regardless of the speed of operation of the blade of the disconnect switch and an arrangement in which the operating mechanism for the cooperating contacts of the attachment serve only as mechanical units and do not have to conduct current to complete the circuit.

The disconnect switch is designed to isolate an electrical circuit when the blade is in the fully disengaged position with respect to'its cooperating jaws. This type of switchcan be opened under no load conditions to com pletely isolate a load and insure the safety of repairmen and other-"personnel during inspection and repair operations.- However, a disconnect switch is designed primarily to provide electrical isolation and its cooperating contacts are not designed to'open on load current. That is, the switch is primarily designed to be opened under no load conditions and, in the event an operator opens same when load current is flowing therethrough, it may result in an are hanging on between the disengaged cooperating contacts and thus result in damage to both the switch and the circuit.

In order to extend the range of function of the disconnect switch, it is common to provide an interrupter attachment for the disconnect switch. The interrupter attachment contacts are electrically connected in in parallel with the cooperating contacts of the disconnect switch at least prior to the complete disengagement of the contacts of the .disconnect switch. Thus, when the disconnect switch contacts are disengaged, all of the load currentwill flow through the interrupter attachment contacts.

A mechanical connection between the disconnect switch blade and the interrupter attachment is operative to disengage the cooperating contacts of the interrupter attachment after the disconnect switch contacts have disengaged. That is, the mechanical interconnection between the disconnect switch and the interrupter attachment is operative to disengage the cooperating contacts of the interrupter attachment after the disconnect switch blade has established suflicient flashover clearance.

Thus, with this arrangement, all of the interrupting duty is taken by the contacts of the interrupter attachment rather than the contacts of the disconnect switch. Thereafter, one of the electrical connections between the interrupter attachment and the disconnect switch is broken so that movement of the blade of the disconnect switch to the full disengaged position will provide a sufiicient airgap to prevent breakdown.

The interrupter attachment also protects the disconnect switch so that it can be closed on a line in which load current will flow. That is, during the closing operation, an electrical and mechanical connection is made.

between'the disconnect switch blade and the interrupter attachment.

Thus, prior to the engagement of the diaconnect switch contacts, the movement of the disconnect switch blade eifects engagement of the contacts of the interrupter attachment. Since these contacts are in parallel with the disconnect switch contacts, all of the closing duty is placed on the interrupter and not on the disconnect switch. Thereafter, the disconnect switch contacts are closed and hence, will not be damaged even though load current may be flowing in the circuit.

In the prior art construction, the interrupter attach ment unit had many disadvantages which the interrupter attachment of the instant invention overcomes.

Heretofore, the interrupter attachment has been constructed with the operating arm interconnected through the operating mechanism directly to the interrupter attachment contacts. Hence, during the initial movement of the operating arm, the interrupter attachment contacts will move with respect to each other even prior to the snap action of the unit. That is, there is a teasing of the interrupter attachment contacts during the initial movement of the operating handle and operating mechanism.

;In the prior art, it has been necessary to provide one of two means to overcome these disadvantages. One solution has been to provide the disconnect switch with snap action so that the motion imparted to the operating handle of the interrupter attachment by the disconnect switch blade would be a snap acting motion and thereby overcome the inherent disadvantage within the interrupter attachment unit. 'However, this has proved tobe an undesirable solution to and/or adaption on a disconnect switch.

vThe second alternative which has heretofore been used to overcome the above noted disadvantage is to provide a predetermined sequence in the operation of the disconnect switch and the interrupter attachment so that the disconnect switch blade does not engage the operating handle of the interrupter attachment until after the disconnect switch contacts have disengaged. Thus, by this means, any possible teasing of the cooperating contacts and the interrupter attachment will not result to destruction or damage to the main contacts of the disconnect switch. However, even this arrangement has not been wholly satisfactory since it requires a predetermined sequence of operation and may result in damage to the contacts of the interrupter attachment.

I have overcome this disadvantage in my novel interrupter attachment by providing lost motion between the operating arm and the contacts of the attachment during both opening and closing operation. That is, during the initial movement of the operating circuit, the cooperating contacts of the interrupter attachment remain either fully engaged or disengaged. It is only after a predetermined movement of the operating arm, at a time when sufiicicnt energy is stored in a toggle spring which ating arm moves of its complete distance of travel before the snap action is imparted to the cooperating contacts. Furthermore, the construction is such that the speed for the full stroke of the contact plunger of the interrupter attachment is completely independent of the speed of travel of the operating arm. Thus, if the disconnect switch blade is opened slowly, the main contacts of the interrupter attachment will remain completely engaged until the operating arm has been moved to approximately 36 of its full distance of travel. At that time, the interrupter contacts will open with snap action at a speed hich is independent of the speed of operation of the Patented Feb. 25,. 19158 the problem since it operating arm. The same sequence will also occur during closing operation.

Thus, with my novel arrangement, it is not necessary to provide any additional or auxiliary means to the disconnect switch to open the blade with snap action nor is it necessary to provide a predetermined sequence of mechanical engagement between the disconnect blade and the operating arm of the interrupter attachment. Fur thermore, by providing this novel arrangement wherein lost motion is provided between the operating arm and the contacts of the interrupter attachment, it is possible to start the opening operation of the'diseonnect switch, stop and reverse the movement to engagement without affectmg the interrupter attachment which was not heretofore possible with the devices of the prior art.

Another disadvantage which has heretofore been en countered in the prior art construction is damage or ineificiency of the interrupting chamber due to the fact that the movable contact in the interrupter attachment does not have straight-line movement. That is, the prior units provided an arrangement wherein the operating means of the housing of. the interrupter attachment is connected directly to the movable contact. Hence, the arcuate movement of the operating means was imparted to the movable contact thereby forcing one end of this member to move in a substantially ar'cuate' path- However, with my instant arrangement, I provide a sliding engagement between one unit of the operating means and the movable contact and also provide a conductive guide member. By this arrangement, the arcuate movement of the operating means'is transferred through the sliding engagement and due to the conducting guide member, the movable contact moves in straightline motion thereby making most effective use of the interrupting chamber and preventing mechanical damage thereto.

Although some prior art devices do have straightline motion of the movable contact of the interrupter attachment, it is achieved by providing an extra member in the drivinglinkage. However, in my novel device, I provide a new and novel means to accomplish straightline motion and at the same time electrical connection to the moving contact assembly.

In addition to this advantage over the prior art arrangement, the conducting guide member provides an electrical connection directly'from the movable contact of the interrupter attachment to the housing of the interrupter attachment without requiring the moving operating means to conduct current. Heretofore, the operating means and its pivotal supports have had to carry all of the load cur rent passing through the cooperating contacts. However, with my novel arrangement, the conductive guide member electrically connects the movable contact directly to the housing so that the operating mechanismdoes not have to conduct current.

The prior art interrupter attachments have provided a first operating arm for disengaging. the contacts and a second operating arm for engaging the contacts. Due to the direct connection between the operating means and the movable contact, it was necessary to .provide this type of arrangement with the opening operating arm extending from one side of the housing and the closing operating arm extending from the opposite side oi? the housing. Thus, regardless of the manner in which this type of construction was mounted, at least one of the operating handles was exposed to the evil of ice formation and the possibility of water leaking into the unit. However, in my novel construction, I have provided an arrangement wherein a single operating arm is utilized to both open and close the cooperating contacts of the interrupter attachment and hence, this unit need extend from only one side of the housing. Thus, if the operating arm is positioned on the lower portion of the housing when mounted on an upright switch, ice formations will not interfere with the operation and also, since it is on the lower side, there will not be the possibility of water leaking into the unit.

In addition to the many practical and mechanical advantages which are achieved by a single opening and closing operating arm, it is also noted that this arrangement provides for an extremely economical construction and also one that is readily adapted for either a left-hand or right-hand operating unit.

Accordingly, one object of my invention is to provide an interrupter attachment for a disconnect switch in which the operating arm and operatingmeans do not impartmovement to the cooperating contacts until after they have reached a predetermined position at which time the'coopcrating contacts are moved to disengaged position with snap action independent of the travel of the operating arm.

Another object of my invention is to provide an arrangement in which the operating arm and operating means initially store energy in a toggle spring during which time the cooperating contacts remain in fully engaged or disengaged position.- Atter a predetermined movement of the operating units, the energy is released from the toggle spring to thereby impart snap action to the cooperating contacts to either engage or disengage these members with snap. action independent of the movement of the operating members.

Another object of my invention is to provide a lost motion connection between the operating mechanism and the cooperating contacts so that the disconnect switch blade does not have to be opened, does not require any special attachment or apparatus to be opened in snap action nor does the apparatus require any special sequence of mechanical interconnection between the disconnect switch and the interrupter attachment.

Another object of my invention is to provide an arrangement whereby a sliding connection between the operating means and the movable contact combined with a conductive guide member impart straight-line motion to the movable contact to thereby make eifective' use of the interrupting chamber and prevent damage thereby.

Another object of my invention is to provide an interrupter attachment with a novel interrupting guide member so that an electrical connection is made directly from the movable contact to the housing of the attachment without requiring the operating means to conduct current.

A still further object of my invention is the provision of a novel construction for an interrupter attachment wherein a single operating arm functions to both open and close the cooperating contacts so that the entire unit can be mounted with the operating arm. downwardly thereby avoiding interference with the unitfrom ice formation and also. reducing the possibility of water seeping into the unit.

Theseand otherobjects of my invention will be apparent from the following description when. taken in connection with the drawings in which:

Figure 1 is a side view of a disconnect switch adapted with an interrupter attachment of my invention.

Figure 2 is a top view of the disconnect switch and interrupter attachment of Figure 1.

Figure 3 is aviewtaken in the direction of the arrows 3-3 of Figure 2 illustrating'the mechanicaland electrical relationship between the interrupter attachment and the disconnect switch. l

Figure 4 is a side view of the interrupter attachment of my invention In this view, the cover of the housing has been removed and portions of the interrupter chamber and interrupter contact are shown in sectional view.

Figure 5 is a view taken inthedirection of the arrows 5-5 of Figure 4 illustrating an end view of the interrupter attachment with portions broken-away.

Figure 6 is aside view of the interrupter attachment illustrating the opposite side of theview shown in Figure 4;

Figure 7 is a sectionalview takenin the direction of the Armin-7 of Figure 4 and illustrates an end view 3 ing means during their initial movement but prior to the disengagement of the cooperating contacts of the interrupter attachment. 1 e

Figure 9c is across-sectional view of the interrupter attachment illustrating the position of the operating compatients in the partially open position. This figure is a snapshot picture taken during the opening operation.

Figure'9d is a cross-sectional view of the interrupter attachment illustrating the position of the various components when the interrupter attachment is in the fully open position.

Figure 9e illustrates a snapshot view of the components while the moving contacts are being moved to their engaged position. I

Figures 1, 2 and 3 illustrate the'manner in which the interrupter attachment of my invention may be applied to a disconnect switch. I The disconnect switch 10 is provided with a blade 11 which is pivotally mounted at 12 for rotation into and out of engagement with jaw 13. The entire unit may be mounted on base 14 and supported by insulators 15 and 16. The disconnect switch blade 10 isfmoved intoengaged and disengaged position with the jaw 13 by means of the hook ring 17 in a manner which is well known in the art and illustrated in Patent Nos. 2,738,402, 2,789,189 and 2,787,690, all assigned to the assignee of the instant application. Thus, in the arrangement illustrated, the current path is from the terminal 18, through the hinge 12; the blade 11 to the jaw 13 and out through the terminal 19.

-An interrupter attachment 30, which will be hereinafte described in detail in connection with Figures 4 through 9,- is mounted by means of bracket 20 on the stationary jaw base 13 of the disconnect switch 10.

A movable :shunt born 22 is rigidly secured to the blade 11 by means of the bracket 23. A stationary shunt born 31 secured by means of a horn clamp 32 and bolts 33sis securedto the housing 35 of the interrupter attachment 30. The cooperating contacts of the interrupter attachment 30 are contained within the interrupter chamber 40. e

In the figures illustrated, the disconnect switch 10 and the interrupter attachment 30 are both in the fully closed position. The supporting bracket 20 ofthe interrupter attachment 30 is-a conductive member so that the stationary contact of the interrupter attachment 30 is elecrically connected to the jaw end of the disconnect switch 10.

As will hereinafter be more fully explained, the movable contact of the interrupter attachment 30 within the arcing chamber 40 is electrically connected to the housing 35. Sincethe arcing born 31 is rigidly secured to the housing 35, an electrical connection is made from the moving contact of the interrupter attachment 30 through the stationary arcing horn 31, the movable arcing horn 32 and the bladell of the switch 10. Thus,--in the position illustrated in the figures, the cooperating contacts of the interrupterattachment 30 are connected in electrical parallel with the main contacts of thedisconnect switch "lt'will be, noted an the electrical connection betweenthe blade 11 andthe movable contact of the interrupter attachment 3.0, which is made .betweenthe'movable arc.-

miners are stationary 'atcing' h'om 31;may be made while the cooperating contacts 11 and 13 of the dis connect switch are in the fully engaged position or, in

some applications, it may be desirable not to have elec- ,trical engagement between the moving arcing horn 22 'and the stationary arcing horn 31 until after opening op- The manner in which the interrupter attachment 30 coordinates with the disconnect switch 10 is as follows.

When the switch is in the fully closed position, a major portion of the load current will flow through the relatively low resistance path provided by the blade 11 and the jaw 13 thereby etfectively bypassing the parallel path provided through the arcing horns 22, 31 and the interrupter attachment 30 mounted on conductive break 20. 25

When it is desired to open the disconnect switch blade 11, the pull ring 30 is pulled toward the open positionso that the blade 11 will disengage the jaw 13 of the disconnect switch 10. However, these cooperating contacts will not be called upon to interrupt any current since there is an alternate electrical path through the interrupter-attachment 30 due to the electrical engagement of the movable and stationary arcing horns 22-'-31-.

The continued movement of the blade 11 of the dis- --connect switch 10 will bring the movable arcing horn 22- into mechanical engagement with the operating lever 50 of the interrupter attachment 30 to thereby rotate this lever in a counterclockwise direction. It will be noted that during this period of time, electrical engagement is still maintained between the blade 11 and the interrupter attachment 30 due to the continued electrical engagement of the arcing horns 22-31.

After the operating lever 50 has been rotated a predetermined number of degrees, as for example 65 as 'zwill hereinafter be more fully explained, the operating mechanism within the interrupter attachment 30 will result in snap action opening operation of the contacts of the interrupter attachment. Thus, all of the interrupting duty will be taken by the cooperating contacts of the interrupter attachment 30 so that no damage will occur to the cooperating contacts of the switch 10.

It will be noted that the arrangement is designed so that the disconnect switch blade 11 establishes a sufficient flashover clearance to the jaw 13 before the cooperating contacts of the interrupter attachment 30 separate. After the load current has been fully interrupted, by the interrupter attachment 30, the operator will continue to move the switch blade 11 toward its disengaged position until i it is approximately from the position illustrated in 'Figure 1. At this point, there is no longer any mechanical or electrical engagement between the interrupter attachment 30 and the blade 11 Since the movable arcing born 22 will have disengaged both the stationary arcing horn 31 and the operating lever 50.

Thus, the disconnect switch 10 is moved from the fully engaged position to the fully disengaged position and: even though load Current was flowing in the circuit, there is no interrupting duty'placed u'pon the disconnect switch since interrupter attachment contacts perform the interruption of the current.- Hence during the opening operation, the interrupter attachment permits the combined unit to function as a load break switch; However,

as' noted, when the disconnect switch 10 is in the 'fully 1 .open position, it is mechanically and electrically disengaged from the interrupter attachment Sit-and hence,

provides the full airgap distance to provide sufiicient isolation for the electrical circuit.

:During the closing operationQthe interrupterattachment 30 also functions to protect the disconnect switch 10 from any damages which might result to the switch in the event it is closed on a hot line. This is achieved. in, the following manner.

During the closing operation, the movable arcing horn 22 of the blade ll engages both the stationary arcing horn 31 and the operating lever 50. The rotation of the. blade 11 toward the closed position rocks the operating lever 50 in a direction to charge a toggle spring, as will hereinafter bemore'fully explained, so that after it has moved a predetermined distance the contacts in the interrupter attachment 30 will close with snap action Thus, an electrical circuit will be completed during the portion of the closing operation from the terminal 18, through the hinge 12, the blade 11, the moving arcing horn 22, the stationary arcing horn 31, the interrupter attachment 3%, the jaw 13 then to the terminal 19.

Upon continued movement of the blade 11 toward the closed position, there will be no damage to the cooperating contacts of the disconnect switch 10 since the closed contacts of the interrupter attachment 30 are connected in parallel therewith and hence, will conduct all of the current during the closing operation. Thus, the disconnect switch 10 can be moved to the fully engaged position without damage to the cooperating contacts.

In the illustration and description in connection with Figures 1 to 3, I have explained the manner in which the interrupter attachment electrically and mechanically coordinate with a disconnect switch.

Figures 4 through 9 illustrate the detailed construction of the interrupter attachment and the manner in which the operating mechanism and cooperating contacts thereof operate.

The details of the interrupter unit are best illustrated in Figures 4, 5, 6, 7 and 8.

As has heretofore been noted, the interrupter attachment 30 is comprised of the housing 35 and the interrupting chamber 40. Referring first to the interrupting chamber 40, the device comprises a main movable contact 51 and a main stationary contact 52. In the position illustrated in Figure 4, the interrupter attachment is in the completely disengaged position. The movable contact 51 is an integral part of the hollow cylindrical conducting member 53 which has a slotted member 54 rigidly secured to the upper end thereof.

A conductive guide member 55 is rigidly secured at its upper end to the housing 35 to thereby make electrical and mechanical engagement therewith. The lower end of the conductive guide member 55 is slit as indicated by the slot 56 and positioned within the hollow cylindrical conducting member 53. The slot 56 in the conductive guide member 55 extends for a substantial distance along the length of the member 55 and serves to bias the guide member 55 toward the inner surface of the hollow cylindrical moving contact 53 to make electrical and mechanical engagement therewith.

The lower end of the hollow cylindrical movable contact 53 is provided with an extending screw 57. A follower 58 of insulated material such as nylon is threadably engaged with the extension screw 57 so that the follower 58, the hollow cylindrical movable contact 53 and the slotted member 54 move together as a single unit.

The cylindrical follower 58 has an external diameter which is slightly less than the internal diameter'of the hollow cylindrical arc chamber liner 59 which may be made of aninsulating material such as nylon or a material which will emit arc extinguishing gases. The are chamherliner 59 is initially slidably positioned Within the arc chamber tube 60 and thereaftersecurely held in position in a manner hereinafter described.

Both "ends of the arc chamber tubes 60 are threaded V with the upper end in threaded engagement with an exetension 61 of .the housing, 35. The lower end. is in threaded engagement with the clamping sleeve62. However, prio rtol the time that the clamping sleeve 62' is brought intotcomplete threaded engagement with the arc chamber tube 6 0, a hollow cylindrical housing 63 is made of material suchas porcelain and is positioned concentric with respect to the cooperating contacts. The upper end of the porcelain housing: 63'is sealed against the lower surface of the housing 35 with a gasket 64 positioned therebetween. The clamping sleeve 62 is then brought into threaded engagement with the arc chamber tube 6.0

and a gasket 65 ispositioned between: the porcelain tube 1 63 and the clamping sleeve 62. e

As clearly illustrated in Figure 4, the lower end of the arc chamber tube 60"is provided with a step section66'.

This step section serves asa guide for insulating ring 66 and the stationary arcing'contact ring 67. These two ring members are initially loosely fitted in concentric alignment with the follower 58 and have an external diameter which is slightly less than the internal diameter of the step portion 66' 9f the arc chamber tube.60. Thereafter, a hollow cylindrical conducting sleeve 68, having substantially the sameexternal diameter as the ring. member 66 and 6,7, is positioned within the arc whichhas a plurality of longitudinal slots thereof curved. Thus, with this. arrangement, the lower end of the stationary contact 70' is in tight fitelectr'ical and mechanical engagement, with. the upper internal portion .of the stationary contacts 69 and the:upper portion'ofzthe stationaryconducting metreber 70 will engage the main movable contact 51 when the.

inwardly as illustrated in Figure 4.

interrupter attachment 30 is in the elosedposition.

It will be noted that the internal diameterof the stationary contact 7flis less'than the external diameter of the movable contact 51 and hence, .due to the slotted arrangement of the stationary contact 70, the stationary contact will be biased toward the movable'contact.

By providing the curved section 'll at the upper end of the stationary member 70 so :that its extreme upper end.

flanges outwardly, the follower 58 and movable contact 51 can move easily into the internal portion of the sta tionary-contact 70 when the interrupter is moved to. the closed position and thereafter, the stationary contact 70 will be biased radially inward toward the movable contact 51.' By rotating the stationary contact 69 into threaded engagement with the clamping sleeve 62, the spacingsleeve 6S urges the arcing contact ring 67, the insulating ring 66 and the .arc' chamber liner tube 59 upwardly until they are allsecurely positioned by a tight fit arrangement.

Thereafter, the-mounting basemuffier 72 is positioned over the lowerpo'rtion of the'arcing chamber 40 and secured by means of'bolts 73to the clamping sleeve 62. The mounting base-mufiler 72 provides a chamber 74 into which hot gases and ionized -air can expand when the cooperating contacts of the interrupter attachment interrupt load current. i I

An opening-75 is provided in the side of the mounting base muffler 72 to exhausthot gases and ionized air.

It .will be noted' that the mounting base is also pro- Figures 1, 2 and 3.'

When the interrupter attachment 30 is in the fully closed position, a current path will be provided from the jaw base 13 of the disconnect switch through the mounting plate 20, through the mounting bolt 76, the base 72,

the clamping sleeve 62,,the base 69, the stationary contact 70, the main movable contact 51, through the hollow cylindrical sleeve 53 of the movable contact to the conductive guide member 55, to the housing 35, the arc horn V clamping member 32 to the stationary arcing horn 31 and back to the blade 11 of the disconnect switch by means I of the movable arcing horn 22. Thus, the interrupter attachment cooperating contacts will be in parallel with the v turn, is controlled by the movement of the blade 11 of i the disconnect switch 10. That is, during the opening operation of the disconnect switch, the movable arcing born 22 engages the protruding pin 41 of the operating lever 50 and during the closing operation, engages the protruding pin 42 of the operating lever 50.

The operating lever 50, mounted on the outside of the housing 35, is rigidly secured to the operating shaft 80 in any desirable manner as for example by a key and keyway v 81 interlocked therebetween.

The operating shaft 80 extends through the one side of the housing 35 and has a first lever 82 rigidly mounted thereon in any desirable manner. The lever 82, therefore, has the same degree of rotation that the operating lever 50 will have since they are both rigidly secured to the operating shaft 80.

An L-shaped lever 83 is pivotally mounted at pivot 84. The .lever 83 is provided with a slot 85 which contains a pin 86 rigidly secured and extending perpendicular to the first lever 82. Thus, a clockwise rotation of the first lever 82, due to the rotation of the operating lever 50 will cause counterclockwise rotation of the second lever 83 due to the sliding engagement by slide 85 and pin 86.

A trip lever 87 has a U-shaped base with one side pivotally mounted on the operating shaft 80 and the other side pivotally mounted at the pivot point 87'. v The pivot point 87 is on the bearing plate 88 which is rigidly secured to the base of the housing 35 by means of the screws 89.

One end of a toggle spring 90 is secured to one extension of the trip lever 87 and the other end of the toggle spring 90 is secured to the base of the second lever 83. It will be noted that a second spring 91 may be providedwith one end secured to the second lever 83 and the opposite end secured to the pin 86 of the first lever 82.

As will hereinafter be more fully explained, the toggle spring 90 serves to store energy during the initial movement of the first and second lever 82 and 83 and thereafter, transfer this energy to the trip lever 87 after the toggle spring 90 has been moved over center so that the trip lever 87 will move with snap action independent of the movement of the first and second lever 82 and 83. The spring 91 serves as a biasing means to maintain the first and second levers 82' and 83 in either their open or closed position.

The third or trip lever 87 is provided with extension arms 92 which have'a guide pin 93 extending there through. The guide pin 93 also extends through the slot 94 and hence is in sliding engagement with member 54 which, as heretofore noted, is rigidly secured to the hollow cylindrical movable contact 53.

. In-Figure 8, there is a circular projection 101 shown dotted on the far side of trip lever 87. The purpose of this projection is to engage alternately faces marked llll'and 103 of the first lever 82 during the opening or V 10 closing operations, respectively. The engagement of 101 with 102 or 103 is to urge the trip lever to pass dead center and thereby to not wholly depend on the toggle spring 90 to urge the trip lever over dead center. This is a semi-positive backup for the spring 90.

A flat cover plate 95 may be positioned on one side of the housing 35 and secured thereto by means of the screws 96.

The manner in which the operating mechanism of Figures 4, 5, 6, 7 and 8 functions will now be described in connection with the sequence of diagrams illustrated in Figures 9a, 9b, 9c and 9d.

Figure 9a illustrates the position of the various components when the interrupter attachment is in the fully closed position. In this position, the toggle spring 90 maintains the trip lever 87 in its extreme clockwise position so that the cooperating contacts 5170 remain in thefully engaged position.

When the disconnect switch is moved toward the open position, the movable arcing horn 22 will engage the pin 41 of the operating lever 50 thereby tending to rock this member in a counterclockwise direction. The counterclockwise rotation of the operating lever 50 will be transmitted throughthe operating shaft to the first lever 82 so that this member will also rock in a clockwise direction. The rotational motion of the first lever 82 will be transmitted by the sliding engagement of pin 86 and slot to the second lever 83.

The second lever will thus rotate in a clockwise direction about its pivot point 84. During this initial period of rotation, energy will be stored in both the toggle spring 90 and the spring 91. It will also be noted that since the lower base of the second lever 83 is being rotated about the pivot point 84, the lower end of the toggle spring 90 and the spring 91 will also be rotated about this pivot point since they are both secured to the second lever 83. Spring 91 is the operating lever spring which acts only to hold the first lever 82 and its attached lever 59 in the extreme position.

As best seen in Figure 9b, the initial movement of both the first and second lever 82 and 83, although effective to move and store energy in the springs 90 and 91, will not move the trip lever 87. In the event the operator recloses the disconnect switch before the toggle spring 90 has been moved over center, both toggle spring 90 and 91 will force the first and second toggles 82 and 83 back to their original position as illustrated in Figure 9a.-

It will be noted that in the event this sequence of operation should occur that the cooperating contacts 5170 of the interrupter attachment 30 will remain in full contact engagement all during this period of time.

That is, since the trip lever 87 has not been moved, lost mitted to the trip lever 87 and, therefore, this unit will rotate in a counterclockwise direction about its pivot point 80-87.

Due to the sliding engagement between the trip lever 87 and the movable contact 53, this energy and motion will be transmitted to the movable contact of the interrupter attachment 30 and hence, the sleeve 53 with and follower 58 will all be moved up--.

its contact 51 wardly.

It will be noted that the sliding engagement due-to: the pin 93 and slot 94 will permit the movable contact 51 to have straightline motion as determined by the con ductive guide member 55 even though the trip lever 8'4 travelsthrough an arcuate path. Thus,.with this ar rangement, maximum use of the interrupting chamberis obtainedwithout the. possibility ofdamage thereto.

Figure 90 illustrates a snap-shot view of theoperating means as the moving contacts are being moved toward the open position. It will be noted also that the stored energy of the springs .90 which is transferred to the trip lever 87 is also transmitted to the movablecontact and hence, the opening movement of .themovable contact 5351 is now independent of the movement of the first and second levers 82 and 83. The operating mechanism will then come to rest in the position illustrated in Figure 9d when the contacts will be in the fully disengaged position.

As has heretofore been noted, the cooperating contacts of the interrupter attachment disengage after the main contacts 1113 of the disconnect switch haveseparated a suificient distance to prevent fiashover therebetween. However, there is an electrical engagement due .to-the moving arcing horn 22 and the stationary arcing horn 31 prior to the time that the cooperating contacts of the interrupter attachment are disengaged.

Following disengagement of the cooperating contacts of the interrupter attachment, the blade 11 of the disconnect switch 10 is rotated a sufficient distance so that the arcing horn 22 will disengage the stationary arcing horn 31 and hence, there will be no electrical connection between the blade 11 andthe interrupter attachment. 30.

The closing operation for the interrupter attachment is a reverse sequence of that above noted. That is, the blade 11 is moved toward the closed position and hence, the moving arcing horn 22 is brought into electrical engagement with the spark arcing horn 31. Thereafter, the moving arcing horn 22 engages the operating lever 50 of the interrupter attachment 30 to rotate this unit in a clockwise direction.

As has heretoforebeen noted, since the operating lever 50 is rigidly secured to the operating shaft 80, the first lever 82 will also'be rotated in a clockwise direction. Due to the sliding. engagement between the first and second levers 82 and'83 and due to the pin 86 and slot 85, the second lever 83 will be rocked in a counterclockwise direction about its fixed pivot 84. During the initial rotation of these two components, energy will be stored in the springs 90 and 91.

It will be noted that during this initial movement of the first and second levers 82 and 83, no motion is imparted to the trip lever 87 and hence, the cooperating contacts 5170 will remain completely disengaged. However, after the toggle spring 90 is moved over center, that is, to the right of the pivot point 80-87, the energy therein will be released to the trip lever 87 and hence, the cooperating contactswill be moved to the engaged position with snap-action.

Figure 9eillustrates a snapshot view of the position of the-components of'the operating means as the contacts are'being moved with snap-action toward their closed position and Figure 9a illustrates the position of the components when the interrupter attachment is in the fully closed position.

It will be noted that the closing operation of the cooperating contacts 5170 occurs independent of the movement of the first and second lever 82 and 83. Thereafter, as blade 11 is continuously moved toward its disengaged position, the main contacts 1113 of the disconnectswitch 10 will be brought into engagement. However, since the parallel contacts of the interrupter attachment have already been brought into engagement, there will be no arcing on the main contacts of the disconnect switch. 7

Thus, in summary, I have provided a novel interrupter attachment fora-disconnect switch wherein'a-single operating lever diiextendsifrom one side of the housing-35 and controls both the opening and closing operating of thccontacts. ThUS IhG interrupter :attachment can be mountedonan upright mounted switchso that the cover plate extends upwardly. Since the operating lever is on the lower side and also since there need beno openings in the cover plate 95, interference with the operation'of the unit due to ice formation will be reduced'and thepossibility of leakage into the housings of, the unit is reduced.

Furthermore, the arrangement of providing lost motion within the operating mechanism so that the cooperating contacts do not move during the initial operation of the operating lever 50 prevents teasing of the operating contacts, insures that they will open and close with snapaction which is independent of the movement of theopcrating levers, will not require special snap-actionopera- -tion .ofthe blade of the disconnect switch nor require able contact so that most efiective use of the interrupting chamber is utilized thereto.

In the foregoing, I have described my invention only in connection with preferred embodiments thereof. Many variations and modifications of the principles ,of my invention within the scope of the description herein are obvious. Accordingly, I prefer to be bound not by the specific disclosure herein but only by the appending without the possibility of damage claims.

I claim:

1. An interrupter attachment for disconnect switch comprising a housing and interrupting chamber; a pair of cooperating contacts positioned within said interrupting chamber; said pair of cooperating contacts being comprised of a stationary contact and a movable contact, operating means associated with said housing to control the operation of said movable contact; a stationary guide means for said movable contact; said movable contact being in electrical and mechanical engagement with said guide means; said operating means operatively connected to said movable contact to move said movable contact with respect to said guide means; said guide means operativeto guide said movable contacts in straight-line motion.

2. An interrupter attachment for a disconnect switch comprised of an interrupting chamber and a housing; a stationary and movable contact positioned within said interrupting chamber; operating means mounted in and on said housing to effect engagementand disengagement comprised of a conductivehousing and an interrupting chamber; a pair ofcooperative contacts positioned within said interrupting chamber; operatingmeans to effect movement of one of said cooperatingcontacts with respect to said other cooperating'contact; a conductive guide -member for-saidone-cooperating contact to guide said contact in straight-line motion; said conductive guide means operatively connected to complete electrical engagement between said last mentioned contact and saidhousing.

4. interrupter attachmentifor a disconnect .switc 13 comprised of a conductive housing and an interrupting chamber; a pair of cooperating contacts positioned within said interrupting chamber; operating means to effect movement of one of said cooperating contacts with respect to said other cooperating contact; a conductive guide member for said one cooperating contact to guide said contact in straight-line motion; one end of said guide means mechanically and electrically connected to said housing; the other end of said conductive guide means biased into mechanical and electrical engagement with said one contact.

5. An interrupter attachment for disconnect switch being comprised of a housing and an interrupting chamber; a pair of cooperating contacts positioned within said interrupting chamber; operating means supported by said housing for moving said cooperating contacts to engaged and disengaged position; said operating means being comprised of a first, second and third member; said first member being connected to said second member by a first toggle spring; said second member being connected to said third member by a second toggle spring; said third member being slidably connected to one of said cooperating contacts to enable straight-line motion between said coopcrating contacts.

6. An interrupter attachment for disconnect switch being comprised of a housing and an interrupting chamber; a pair of cooperating contacts positioned within said interrupting chamber; operating means supported by said housing for moving said cooperating contacts to engaged and disengaged position; said operating means being comprised of a first, second and third member: said first member being connected to said second member by a first toggle spring; said second member being connected to said third member by a second toggle spring; said third member operatively connected to one of said cooperating contacts; said first toggle spring operatively connected between said first member and said second member to impart clockwise rotation to said second member when said first member is rotated in a clockwise direction; said second toggle spring ineffective to transmit motion from said second member to said third member during the initial movement of said first and second member.

7. An interrupter attachment for disconnect switch being comprised of a housing and an interrupting chamber; a pair of cooperating contacts positioned within said interrupting chamber; operating means supported by said housing for moving said cooperating contacts to engaged and disengaged position; said operating means being comprised of a first, second and third member; said first member being connected to said second member by a first toggle spring; said second member being connected to said third member by a second toggle spring; said third member operatively connected to one of said cooperating contacts; said first toggle spring operatively connected between said first member and said second member to impart clockwise rotation to said second member when said first member is rotated in a clockwise direction; said second toggle spring ineffective to transmit motion from said second member to said third member during the initial movement of said first and second member; a first fixed pivot on said housing for said first and third member; a second fixed pivot on said housing for said second member.

8. An interrupter attachment for disconnect switch being comprised of a housing and an interrupting chamber; a pair of cooperating contacts positioned within said interrupting chamber; operating means supported by said housing for moving said cooperating contacts to engaged and disengaged position; said operating means being comprised of a first, second and third member; said first member being connected to said second member by a first toggle spring; said second member being connected to said third member by a second toggle spring; said third member operatively connected to one of said cooperating contacts; said first toggle spring operatively connected r 14 between said first member and said second member to impart clockwise rotation to said second member when said first member is rotated in a clockwise direction; said second toggle spring ineffective to transmit motion from said second member to said third member during the initial movement of said first and second member; an operating shaft extending through one side of said housing; said first member rigidly secured to said operating shaft and operated thereby; said third member pivotally mounted on said operating shaft; a fixed pivot on said housing removed from said operating shaft for pivotally supporting said second member; one end of said first toggle spring secured to said first member and the other end of said first toggle spring secured to said second member; said first toggle spring effective to impart movement to said second member in a second direction when said first member is moved in a first direction; said second toggle spring ineffective to impart movement to said third memher during the initial movement of said first and second member; said first and second member operatively connected to move said second toggle spring over the center line of said third member following initial movement of said first and second member to thereby impart snap action to said third member independent of the movement of said first and second member.

9. In an interrupter attachment comprised of a housing and an interrupting chamber; a pair of cooperating contacts maintained within said interrupting chamber and having an engaged and disengaged position; operating means for moving said cooperating contacts into said engaged and disengaged position with snap action; said operating means being comprised of an operating shaft extending through one side of said housing; a first member secured to said operating shaft; a third member pivotally mounted on said operating shaft; a second member pivotally mounted on said one side of said housing; said first and second member slidably interconnected; said second member interconnected with said third member by a toggle spring; said slidable interconnection between said first and second member effective to impart clockwise rotation to said second member when said first member is rotated in a counterclockwise direction; said toggle spring ineffective to impart motion from said second member to said third member during the initial movement of said first and second member; movement of said toggle spring to overcenter position by said first and second member operative to cause rotation of said third member about said operating shaft; said third member operatively connected to one of said cooperating contacts to impart snap action to said cooperating contacts.

10. An interrupter attachment for disconnect switch comprising a housing and an interrupter chamber; a pair of cooperating contacts contained within said interrupter chamber having an engaged and disengaged position; operating means to control the position of said cooperating contacts with respect to each other; said operating means being comprised of a shaft extending through one side of said housing; a first member rigidly secured to said first operating shaft; a second member pivoted on said operating shaft; said first operating shaft pivotally mounted on said one side of said housing; said first and second member slidably interconnected; a toggle spring for said third member; said first and second member operative to store energy in said toggle spring during the initial movement of said first and second member; said toggle spring ineffective to release said stored energy to said third member during the initial movement of said first and second member; said third member operatively connected to one of said pair of said cooperating contacts; said pair of cooperating contacts remaining in full engaged position while said first and second member are storing energy in said toggle spring; movement of said first and second member to a predetermined position effective to transfer the stored energy in said toggle spring to said third mem- References Cited in the file of this pat ept UNITED STATES PATENTS 16 Lindell et a1. June 20, 1944 Baker L Dec. 19, 1944. Froland Jan. 13, 1948 Hart June 17, 1952 Linden Dec. 9, 1952 Owens et a1. Dec. 14, 1954 Ling'al, Oct. 30,1956 

